src/common/kernel-ctl/kernel-ctl.c

   1 /*
   2  * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *               2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License, version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #define _LGPL_SOURCE
  21 #define __USE_LINUX_IOCTL_DEFS
  22 #include <sys/ioctl.h>
  23 #include <string.h>
  24 #include <common/align.h>
  25 #include <errno.h>
  26 #include <stdarg.h>
  27 #include <assert.h>
  28 #include <common/time.h>
  29
  30 #include "kernel-ctl.h"
  31 #include "kernel-ioctl.h"
  32
  33 #define LTTNG_IOCTL_CHECK(fildes, request, ...) ({      \
  34         int ret = ioctl(fildes, request, ##__VA_ARGS__);\
  35         assert(ret <= 0);                               \
  36         !ret ? 0 : -errno;                              \
  37 })
  38
  39 #define LTTNG_IOCTL_NO_CHECK(fildes, request, ...) ({   \
  40         int ret = ioctl(fildes, request, ##__VA_ARGS__);\
  41         ret >= 0 ? ret : -errno;                        \
  42 })
  43
  44 /*
  45  * This flag indicates which version of the kernel ABI to use. The old
  46  * ABI (namespace _old) does not support a 32-bit user-space when the
  47  * kernel is 64-bit. The old ABI is kept here for compatibility but is
  48  * deprecated and will be removed eventually.
  49  */
  50 static int lttng_kernel_use_old_abi = -1;
  51
  52 /*
  53  * Execute the new or old ioctl depending on the ABI version.
  54  * If the ABI version is not determined yet (lttng_kernel_use_old_abi = -1),
  55  * this function tests if the new ABI is available and otherwise fallbacks
  56  * on the old one.
  57  * This function takes the fd on which the ioctl must be executed and the old
  58  * and new request codes.
  59  * It returns the return value of the ioctl executed.
  60  */
  61 static inline int compat_ioctl_no_arg(int fd, unsigned long oldname,
  62                 unsigned long newname)
  63 {
  64         int ret;
  65
  66         if (lttng_kernel_use_old_abi == -1) {
  67                 ret = LTTNG_IOCTL_NO_CHECK(fd, newname);
  68                 if (!ret) {
  69                         lttng_kernel_use_old_abi = 0;
  70                         goto end;
  71                 }
  72                 lttng_kernel_use_old_abi = 1;
  73         }
  74         if (lttng_kernel_use_old_abi) {
  75                 ret = LTTNG_IOCTL_NO_CHECK(fd, oldname);
  76         } else {
  77                 ret = LTTNG_IOCTL_NO_CHECK(fd, newname);
  78         }
  79
  80 end:
  81         return ret;
  82 }
  83
  84 int kernctl_create_session(int fd)
  85 {
  86         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION,
  87                         LTTNG_KERNEL_SESSION);
  88 }
  89
  90 /* open the metadata global channel */
  91 int kernctl_open_metadata(int fd, struct lttng_channel_attr *chops)
  92 {
  93         struct lttng_kernel_channel channel;
  94
  95         if (lttng_kernel_use_old_abi) {
  96                 struct lttng_kernel_old_channel old_channel;
  97
  98                 memset(&old_channel, 0, sizeof(old_channel));
  99                 old_channel.overwrite = chops->overwrite;
 100                 old_channel.subbuf_size = chops->subbuf_size;
 101                 old_channel.num_subbuf = chops->num_subbuf;
 102                 old_channel.switch_timer_interval = chops->switch_timer_interval;
 103                 old_channel.read_timer_interval = chops->read_timer_interval;
 104                 old_channel.output = chops->output;
 105
 106                 memset(old_channel.padding, 0, sizeof(old_channel.padding));
 107                 /*
 108                  * The new channel padding is smaller than the old ABI so we use the
 109                  * new ABI padding size for the memcpy.
 110                  */
 111                 memcpy(old_channel.padding, chops->padding, sizeof(chops->padding));
 112
 113                 return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_OLD_METADATA,
 114                                 &old_channel);
 115         }
 116
 117         memset(&channel, 0, sizeof(channel));
 118         channel.overwrite = chops->overwrite;
 119         channel.subbuf_size = chops->subbuf_size;
 120         channel.num_subbuf = chops->num_subbuf;
 121         channel.switch_timer_interval = chops->switch_timer_interval;
 122         channel.read_timer_interval = chops->read_timer_interval;
 123         channel.output = chops->output;
 124         memcpy(channel.padding, chops->padding, sizeof(chops->padding));
 125
 126         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_METADATA, &channel);
 127 }
 128
 129 int kernctl_create_channel(int fd, struct lttng_channel_attr *chops)
 130 {
 131         struct lttng_kernel_channel channel;
 132
 133         memset(&channel, 0, sizeof(channel));
 134         if (lttng_kernel_use_old_abi) {
 135                 struct lttng_kernel_old_channel old_channel;
 136
 137                 old_channel.overwrite = chops->overwrite;
 138                 old_channel.subbuf_size = chops->subbuf_size;
 139                 old_channel.num_subbuf = chops->num_subbuf;
 140                 old_channel.switch_timer_interval = chops->switch_timer_interval;
 141                 old_channel.read_timer_interval = chops->read_timer_interval;
 142                 old_channel.output = chops->output;
 143
 144                 memset(old_channel.padding, 0, sizeof(old_channel.padding));
 145                 /*
 146                  * The new channel padding is smaller than the old ABI so we use the
 147                  * new ABI padding size for the memcpy.
 148                  */
 149                 memcpy(old_channel.padding, chops->padding, sizeof(chops->padding));
 150
 151                 return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_OLD_CHANNEL,
 152                                 &old_channel);
 153         }
 154
 155         channel.overwrite = chops->overwrite;
 156         channel.subbuf_size = chops->subbuf_size;
 157         channel.num_subbuf = chops->num_subbuf;
 158         channel.switch_timer_interval = chops->switch_timer_interval;
 159         channel.read_timer_interval = chops->read_timer_interval;
 160         channel.output = chops->output;
 161         memcpy(channel.padding, chops->padding, sizeof(chops->padding));
 162
 163         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_CHANNEL, &channel);
 164 }
 165
 166 int kernctl_syscall_mask(int fd, char **syscall_mask, uint32_t *nr_bits)
 167 {
 168         struct lttng_kernel_syscall_mask kmask_len, *kmask = NULL;
 169         size_t array_alloc_len;
 170         char *new_mask;
 171         int ret = 0;
 172
 173         if (!syscall_mask) {
 174                 ret = -1;
 175                 goto end;
 176         }
 177
 178         if (!nr_bits) {
 179                 ret = -1;
 180                 goto end;
 181         }
 182
 183         kmask_len.len = 0;
 184         ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SYSCALL_MASK, &kmask_len);
 185         if (ret) {
 186                 goto end;
 187         }
 188
 189         array_alloc_len = ALIGN(kmask_len.len, 8) >> 3;
 190
 191         kmask = zmalloc(sizeof(*kmask) + array_alloc_len);
 192         if (!kmask) {
 193                 ret = -1;
 194                 goto end;
 195         }
 196
 197         kmask->len = kmask_len.len;
 198         ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SYSCALL_MASK, kmask);
 199         if (ret) {
 200                 goto end;
 201         }
 202
 203         new_mask = realloc(*syscall_mask, array_alloc_len);
 204         if (!new_mask) {
 205                 ret = -1;
 206                 goto end;
 207         }
 208         memcpy(new_mask, kmask->mask, array_alloc_len);
 209         *syscall_mask = new_mask;
 210         *nr_bits = kmask->len;
 211
 212 end:
 213         free(kmask);
 214         return ret;
 215 }
 216
 217 int kernctl_track_pid(int fd, int pid)
 218 {
 219         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_TRACK_PID, pid);
 220 }
 221
 222 int kernctl_untrack_pid(int fd, int pid)
 223 {
 224         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_UNTRACK_PID, pid);
 225 }
 226
 227 int kernctl_list_tracker_pids(int fd)
 228 {
 229         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS);
 230 }
 231
 232 int kernctl_session_regenerate_metadata(int fd)
 233 {
 234         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_METADATA_REGEN);
 235 }
 236
 237 int kernctl_session_regenerate_statedump(int fd)
 238 {
 239         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_STATEDUMP);
 240 }
 241
 242 int kernctl_session_set_name(int fd, const char *name)
 243 {
 244         struct lttng_kernel_session_name session_name;
 245
 246         strncpy(session_name.name, name, LTTNG_KERNEL_SESSION_NAME_LEN);
 247
 248         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_SET_NAME,
 249                         &session_name);
 250 }
 251
 252 int kernctl_session_set_creation_time(int fd, time_t time)
 253 {
 254         int ret;
 255         struct lttng_kernel_session_creation_time creation_time;
 256
 257         ret = time_t_to_ISO8601(creation_time.iso8601, sizeof(creation_time.iso8601), time);
 258         if (ret) {
 259                 return -1;
 260         }
 261
 262         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_SET_CREATION_TIME,
 263                         &creation_time);
 264 }
 265
 266 int kernctl_create_stream(int fd)
 267 {
 268         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_STREAM,
 269                         LTTNG_KERNEL_STREAM);
 270 }
 271
 272 int kernctl_create_event(int fd, struct lttng_kernel_event *ev)
 273 {
 274         if (lttng_kernel_use_old_abi) {
 275                 struct lttng_kernel_old_event old_event;
 276
 277                 memset(&old_event, 0, sizeof(old_event));
 278                 memcpy(old_event.name, ev->name, sizeof(old_event.name));
 279                 old_event.instrumentation = ev->instrumentation;
 280                 switch (ev->instrumentation) {
 281                 case LTTNG_KERNEL_KPROBE:
 282                         old_event.u.kprobe.addr = ev->u.kprobe.addr;
 283                         old_event.u.kprobe.offset = ev->u.kprobe.offset;
 284                         memcpy(old_event.u.kprobe.symbol_name,
 285                                 ev->u.kprobe.symbol_name,
 286                                 sizeof(old_event.u.kprobe.symbol_name));
 287                         break;
 288                 case LTTNG_KERNEL_KRETPROBE:
 289                         old_event.u.kretprobe.addr = ev->u.kretprobe.addr;
 290                         old_event.u.kretprobe.offset = ev->u.kretprobe.offset;
 291                         memcpy(old_event.u.kretprobe.symbol_name,
 292                                 ev->u.kretprobe.symbol_name,
 293                                 sizeof(old_event.u.kretprobe.symbol_name));
 294                         break;
 295                 case LTTNG_KERNEL_FUNCTION:
 296                         memcpy(old_event.u.ftrace.symbol_name,
 297                                         ev->u.ftrace.symbol_name,
 298                                         sizeof(old_event.u.ftrace.symbol_name));
 299                         break;
 300                 default:
 301                         break;
 302                 }
 303
 304                 return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_OLD_EVENT,
 305                                 &old_event);
 306         }
 307         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_EVENT, ev);
 308 }
 309
 310 int kernctl_add_context(int fd, struct lttng_kernel_context *ctx)
 311 {
 312         if (lttng_kernel_use_old_abi) {
 313                 struct lttng_kernel_old_context old_ctx;
 314
 315                 memset(&old_ctx, 0, sizeof(old_ctx));
 316                 old_ctx.ctx = ctx->ctx;
 317                 /* only type that uses the union */
 318                 if (ctx->ctx == LTTNG_KERNEL_CONTEXT_PERF_CPU_COUNTER) {
 319                         old_ctx.u.perf_counter.type =
 320                                 ctx->u.perf_counter.type;
 321                         old_ctx.u.perf_counter.config =
 322                                 ctx->u.perf_counter.config;
 323                         memcpy(old_ctx.u.perf_counter.name,
 324                                 ctx->u.perf_counter.name,
 325                                 sizeof(old_ctx.u.perf_counter.name));
 326                 }
 327                 return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_OLD_CONTEXT, &old_ctx);
 328         }
 329         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_CONTEXT, ctx);
 330 }
 331
 332
 333 /* Enable event, channel and session LTTNG_IOCTL_CHECK */
 334 int kernctl_enable(int fd)
 335 {
 336         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_ENABLE,
 337                         LTTNG_KERNEL_ENABLE);
 338 }
 339
 340 /* Disable event, channel and session LTTNG_IOCTL_CHECK */
 341 int kernctl_disable(int fd)
 342 {
 343         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_DISABLE,
 344                         LTTNG_KERNEL_DISABLE);
 345 }
 346
 347 int kernctl_start_session(int fd)
 348 {
 349         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_START,
 350                         LTTNG_KERNEL_SESSION_START);
 351 }
 352
 353 int kernctl_stop_session(int fd)
 354 {
 355         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_STOP,
 356                         LTTNG_KERNEL_SESSION_STOP);
 357 }
 358
 359 int kernctl_filter(int fd, struct lttng_filter_bytecode *filter)
 360 {
 361         struct lttng_kernel_filter_bytecode *kb;
 362         uint32_t len;
 363         int ret;
 364
 365         /* Translate bytecode to kernel bytecode */
 366         kb = zmalloc(sizeof(*kb) + filter->len);
 367         if (!kb)
 368                 return -ENOMEM;
 369         kb->len = len = filter->len;
 370         kb->reloc_offset = filter->reloc_table_offset;
 371         kb->seqnum = filter->seqnum;
 372         memcpy(kb->data, filter->data, len);
 373         ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_FILTER, kb);
 374         free(kb);
 375         return ret;
 376 }
 377
 378 int kernctl_add_callsite(int fd, struct lttng_kernel_event_callsite *callsite)
 379 {
 380         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_ADD_CALLSITE, callsite);
 381 }
 382
 383 int kernctl_tracepoint_list(int fd)
 384 {
 385         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_TRACEPOINT_LIST,
 386                         LTTNG_KERNEL_TRACEPOINT_LIST);
 387 }
 388
 389 int kernctl_syscall_list(int fd)
 390 {
 391         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_SYSCALL_LIST);
 392 }
 393
 394 int kernctl_tracer_version(int fd, struct lttng_kernel_tracer_version *v)
 395 {
 396         int ret;
 397
 398         if (lttng_kernel_use_old_abi == -1) {
 399                 ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 400                 if (!ret) {
 401                         lttng_kernel_use_old_abi = 0;
 402                         goto end;
 403                 }
 404                 lttng_kernel_use_old_abi = 1;
 405         }
 406         if (lttng_kernel_use_old_abi) {
 407                 struct lttng_kernel_old_tracer_version old_v;
 408
 409                 ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_OLD_TRACER_VERSION, &old_v);
 410                 if (ret) {
 411                         goto end;
 412                 }
 413                 v->major = old_v.major;
 414                 v->minor = old_v.minor;
 415                 v->patchlevel = old_v.patchlevel;
 416         } else {
 417                 ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 418         }
 419
 420 end:
 421         return ret;
 422 }
 423
 424 int kernctl_tracer_abi_version(int fd,
 425                 struct lttng_kernel_tracer_abi_version *v)
 426 {
 427         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_TRACER_ABI_VERSION, v);
 428 }
 429
 430 int kernctl_wait_quiescent(int fd)
 431 {
 432         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_WAIT_QUIESCENT,
 433                         LTTNG_KERNEL_WAIT_QUIESCENT);
 434 }
 435
 436 int kernctl_buffer_flush(int fd)
 437 {
 438         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_FLUSH);
 439 }
 440
 441 int kernctl_buffer_flush_empty(int fd)
 442 {
 443         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_FLUSH_EMPTY);
 444 }
 445
 446 /* returns the version of the metadata. */
 447 int kernctl_get_metadata_version(int fd, uint64_t *version)
 448 {
 449         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_METADATA_VERSION, version);
 450 }
 451
 452 int kernctl_metadata_cache_dump(int fd)
 453 {
 454         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_METADATA_CACHE_DUMP);
 455 }
 456
 457 /* Buffer operations */
 458
 459 /* For mmap mode, readable without "get" operation */
 460
 461 /* returns the length to mmap. */
 462 int kernctl_get_mmap_len(int fd, unsigned long *len)
 463 {
 464         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_MMAP_LEN, len);
 465 }
 466
 467 /* returns the maximum size for sub-buffers. */
 468 int kernctl_get_max_subbuf_size(int fd, unsigned long *len)
 469 {
 470         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_MAX_SUBBUF_SIZE, len);
 471 }
 472
 473 /*
 474  * For mmap mode, operate on the current packet (between get/put or
 475  * get_next/put_next).
 476  */
 477
 478 /* returns the offset of the subbuffer belonging to the mmap reader. */
 479 int kernctl_get_mmap_read_offset(int fd, unsigned long *off)
 480 {
 481         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_MMAP_READ_OFFSET, off);
 482 }
 483
 484 /* returns the size of the current sub-buffer, without padding (for mmap). */
 485 int kernctl_get_subbuf_size(int fd, unsigned long *len)
 486 {
 487         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_SUBBUF_SIZE, len);
 488 }
 489
 490 /* returns the size of the current sub-buffer, without padding (for mmap). */
 491 int kernctl_get_padded_subbuf_size(int fd, unsigned long *len)
 492 {
 493         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_PADDED_SUBBUF_SIZE, len);
 494 }
 495
 496 /* Get exclusive read access to the next sub-buffer that can be read. */
 497 int kernctl_get_next_subbuf(int fd)
 498 {
 499         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_NEXT_SUBBUF);
 500 }
 501
 502
 503 /* Release exclusive sub-buffer access, move consumer forward. */
 504 int kernctl_put_next_subbuf(int fd)
 505 {
 506         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_PUT_NEXT_SUBBUF);
 507 }
 508
 509 /* snapshot */
 510
 511 /* Get a snapshot of the current ring buffer producer and consumer positions */
 512 int kernctl_snapshot(int fd)
 513 {
 514         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_SNAPSHOT);
 515 }
 516
 517 /*
 518  * Get a snapshot of the current ring buffer producer and consumer positions,
 519  * regardless of whether or not the two positions are contained within the
 520  * same sub-buffer.
 521  */
 522 int kernctl_snapshot_sample_positions(int fd)
 523 {
 524         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS);
 525 }
 526
 527 /* Get the consumer position (iteration start) */
 528 int kernctl_snapshot_get_consumed(int fd, unsigned long *pos)
 529 {
 530         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_SNAPSHOT_GET_CONSUMED, pos);
 531 }
 532
 533 /* Get the producer position (iteration end) */
 534 int kernctl_snapshot_get_produced(int fd, unsigned long *pos)
 535 {
 536         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_SNAPSHOT_GET_PRODUCED, pos);
 537 }
 538
 539 /* Get exclusive read access to the specified sub-buffer position */
 540 int kernctl_get_subbuf(int fd, unsigned long *len)
 541 {
 542         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_SUBBUF, len);
 543 }
 544
 545 /* Release exclusive sub-buffer access */
 546 int kernctl_put_subbuf(int fd)
 547 {
 548         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_PUT_SUBBUF);
 549 }
 550
 551 /* Returns the timestamp begin of the current sub-buffer. */
 552 int kernctl_get_timestamp_begin(int fd, uint64_t *timestamp_begin)
 553 {
 554         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN,
 555                         timestamp_begin);
 556 }
 557
 558 /* Returns the timestamp end of the current sub-buffer. */
 559 int kernctl_get_timestamp_end(int fd, uint64_t *timestamp_end)
 560 {
 561         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_END,
 562                         timestamp_end);
 563 }
 564
 565 /* Returns the number of discarded events in the current sub-buffer. */
 566 int kernctl_get_events_discarded(int fd, uint64_t *events_discarded)
 567 {
 568         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED,
 569                         events_discarded);
 570 }
 571
 572 /* Returns the content size in the current sub-buffer. */
 573 int kernctl_get_content_size(int fd, uint64_t *content_size)
 574 {
 575         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_CONTENT_SIZE,
 576                         content_size);
 577 }
 578
 579 /* Returns the packet size in the current sub-buffer. */
 580 int kernctl_get_packet_size(int fd, uint64_t *packet_size)
 581 {
 582         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_PACKET_SIZE,
 583                         packet_size);
 584 }
 585
 586 /* Returns the stream id of the current sub-buffer. */
 587 int kernctl_get_stream_id(int fd, uint64_t *stream_id)
 588 {
 589         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_STREAM_ID,
 590                         stream_id);
 591 }
 592
 593 /* Returns the current timestamp. */
 594 int kernctl_get_current_timestamp(int fd, uint64_t *ts)
 595 {
 596         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP,
 597                         ts);
 598 }
 599
 600 /* Returns the packet sequence number of the current sub-buffer. */
 601 int kernctl_get_sequence_number(int fd, uint64_t *seq)
 602 {
 603         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_SEQ_NUM, seq);
 604 }
 605
 606 /* Returns the stream instance id. */
 607 int kernctl_get_instance_id(int fd, uint64_t *id)
 608 {
 609         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_INSTANCE_ID, id);
 610 }